1. Field of the Invention
The invention pertains to rotary joints for supplying heat transfer medium to rotating drums or rolls and is particularly suitable for use with rapidly rotating drums or rolls requiring a high degree of mounting accuracy of the rotary joint on the drum journal.
2. Description of the Related Art 9
Rotating drums and journals containing hot or cold heat transfer mediums such as water or stream are commonly used in the manufacture of paper, fabric and the like. The article being treated passes over the drum or roll periphery during heat transfer, and paper producing mills, for instance, use many such rotating drums to control the paper moisture content and other product characteristics. Over the years, the assignee has developed a variety of rotary joints adapted to be mounted upon a journal of a rotating drum or roll to permit steam or water to be introduced into the drum, or removed therefrom, and reference is made to U.S. Pat. Nos. 3,242,583; 3,498,591; 3,594,019; 3,606,394; 3,874,707; 4,254,974; 4,262,940; 4,606,561 and 4,758,026. Such patents are typical of rotary joint constructions used to introduce or remove heat transfer medium relative to rotating drums or rolls.
In the color printing industry heat transfer drums and rolls are used which rotate at considerably higher rates of revolution than used in paper and fabric manufacture. For instance, the color printing industry utilizes drums or rolls rotating up to 6,000 RPM. In such installations the rotary joints used with such apparatus must be capable of handling the high rates of revolutions and still maintain the required fluid tight relationships between the seals necessary to prevent leakage and provide an effective flow of heat transfer medium to or from the rotating roll or drum.
With journals rotating up to 6,000 RPM conventional apparatus for mounting the rotary joint upon the journals is unsatisfactory due to the very accurate requirements for concentrically mounting the joint with respect to the axis of journal rotation. It is known to thread the rotary joint nipple into the threads of the journal bore, however, such threaded connections do not assure concentricity because of the tolerances in the threads, and the use of gaskets between the journal and joint nipple permits the gaskets to be unevenly compressed resulting in eccentricity of the joint nipple axis of rotation with respect to the journal rotation axis.